World War II
In 1940 most of France was occupied by Nazi Germany, and Phibun immediately set out to avenge Siam's humiliations by France in 1893 and 1904 when the French limited the borders of Siam to the north by forcing a series of treaties. Luang Wichint wrote a number of popular dramas that glorified the idea of many ethnic groups belonging to one greater "Thai" empire and condemned the evils of European colonial rule. Irredentist and anti-French demonstrations were incessantly held around Bangkok, and in late 1940 border skirmishes erupted along the Mekhong frontier. In 1941, the skirmishes became a small scale war between Vichy France and Thailand. The Thai forces dominated the war on the ground and in the air, but suffered a crushing naval defeat at the battle of Koh Chang. The Japanese then stepped in to mediate the conflict. The final settlement thus gave back to Thailand a number of the disputed areas in Laos and Cambodia.